Tach Wiring

[74RRGTX440]

Hey guys, I have a 74 RR that currently has a clock instead of a tach, if I replace the clock with an OEM style tach, what would I need to do to get it wired properly?

 

[philcollins]

https://www.ebay.com/itm/1972-73-74...262658?hash=item5b57df1902:g:1coAAOSwQmJcYesK

 

[74RRGTX440]

Thank you sir.